Share this post

Link to post

Share on other sites

it sounds really like your hotend is not getting warm enough to melt the PLA... only a little and then the extruder tries to force it into the hotend... no chance..... do you have any way in measuring how warm the alu block is actually getting... ?

not that there is a problem with the sensor or the sensor and heat element are not properly held into the alu block ?

you could experiment... and take the 4 long screws out, turn on the hot end with your ultcontroller to 220 degrees....

then holding the hot end away from the main body, try and physically push a little pla in through the top and down...

if its correctly 220 degrees, the pla should come running out like a happy snake... if not then your sensor is not ready things right....

Share this post

Link to post

Share on other sites

You could point a hairdryer on your hot end, and see if the temperature rises accordingly. Or fully lower your build platform and put a electric kettle on it, or just a cup of boiled water. You know it should be 100°C

As an alternative, can you take out the teflon tube and manually push a new fresh piece of filament through?

You should feel zero friction. If you do feel an edge this could also prevent a proper extrusion and create plugs.

After you clean everything, please make sure when you assemble everything back together everything is tight.

Share this post

Link to post

Share on other sites

Maybe its a moisture issue? I keep my filament in a dry box, but every now and then I'll test something with a piece of PLA that has been sitting out for a while. It seems like it will push through fine for a little while, then gets harder to push. Then when I pull the piece out, the stuff in the nozzle starts bubbling back out the top.

Share this post

Link to post

Share on other sites

I recently bought rather cheap filament from a new source (because living in switzerland, i wanted to avoid the hassle with customs).

I started having rather similar problems: one print works fairly smooth. then the second, or the third, if it was smaller prints, start underextruding and jamming.

Removing the filament, cutting off the lump, reinserting, heating to 250° and pushing by hand results in first very bad flow, then eventually charred bits in the extruded filament, and sooner or later (later, for the most part...) i get clean material.

Actually to me it seems the material is grainy or something.

Since i use hite filament a lot the charred bits show up clearly.

I found that the filament diameter needs to be measured rather exactly for longer prints, since, obviously, any measuring faults add up over time. And this cheaper filament is very unforgiving.

I also started to retract the filament ratehr far (way out of the hot end, to be on the safe side, after each longer print.

Our picks

We're not only trying to always make Ultimaker Cura better with the usual new features and improvements we build, but we're also trying to make it more pleasant to operate. The interface was the focus for the upcoming release, from which we would already like to present you the first glance.

19 replies

Picked By

Designing for light-weight parts is becoming more important, and I’m a firm believer in the need to produce lighter weight, less over-engineered parts for the future. This is for sustainability reasons because we need to be using less raw materials and, in things like transportation, it impacts the energy usage of the product during it’s service life.